DC Battery storage into Tesla Powerwall

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Joeboy
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Re: DC Battery storage into Tesla Powerwall

#11

Post by Joeboy »

NikoV6 wrote: Tue Feb 07, 2023 1:26 pm
Fintray wrote: Tue Feb 07, 2023 1:19 pm
NikoV6 wrote: Tue Feb 07, 2023 1:09 pm Clearly, being an AC system PowerWall will not take DC directly.

However, as the DC generation from my solar array could be stored in a DC battery, then converted to AC by hybrid inverter. Surely its just a case of adding that inverter output to Tesla gateway in the same manner as the output of the current solar inverter.

Or is that noob talk? :lol:

Not an electrical specialist, I'm a mechanical engineer!
That would be my method of doing it.
PylonTech US5000 4.8kWh for £1650ish looks good value unless your research has found better?
Just for reference on my own battery storage build in a previous thread.

'£1,687- 15 of LF280K (A) batteries incl del, bus bars n bolts
£60.72 - 1 of 15s 5A balance board.
£60 framework and bolts
£20 DC-DC variable 20A buckboard (battery charger)
£38 Amp clamp (AC AND DC capable)
£60 Frankenstein breaker & 2 125A fuses
£26 2 of 2mtr lengths 25mm2 cable
£12 Hammer crimper
£36 Solder kit gear, 18awg cable & heatshrink kit
£24 lugs for AWG2 & AWG18 wire, reel of solder.
£13 100A busbar to match spare.
£14 1mtr each of red & black 25mm2 cable
£2,063 total

£153.49 per kWh installed
From the above list I could remove the buckboard (unused) and half a bag each of two sizes of lugs. Being an up in the air install changed it also. I could easily see someone achieving sub £140 per kWh depending on their current tools and skills.
Multiply that figure by the specific Pylontech unit required and its beyond a no brainer by a crazy margin. '
Last edited by Joeboy on Tue Feb 07, 2023 2:54 pm, edited 1 time in total.
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Moxi
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Re: DC Battery storage into Tesla Powerwall

#12

Post by Moxi »

Not a problem if you use a separate charger and use the grid tie inverter to just feed the system though. You could set the charger on timer to take advantage of any tariff you might be on or even add in DC charging if you have the space for more panels.

The possibilities are endless :)

Moxi
NikoV6
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Re: DC Battery storage into Tesla Powerwall

#13

Post by NikoV6 »

Moxi wrote: Tue Feb 07, 2023 2:02 pm Not a problem if you use a separate charger and use the grid tie inverter to just feed the system though. You could set the charger on timer to take advantage of any tariff you might be on or even add in DC charging if you have the space for more panels.

The possibilities are endless :)

Moxi
Was thinking I currently have three strings, I could effectively divert one to a new hybrid inverter and then on to the PowerWall.
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Fintray
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Re: DC Battery storage into Tesla Powerwall

#14

Post by Fintray »

NikoV6 wrote: Tue Feb 07, 2023 1:47 pm
Fintray wrote: Tue Feb 07, 2023 1:34 pm
NikoV6 wrote: Tue Feb 07, 2023 1:26 pm

PylonTech US5000 4.8kWh for £1650ish looks good value unless your research has found better?
I was thinking more along the lines of the 280A batteries in a series string of 16 and into a hybrid inverter.
For around £10K you should be able to get about a 54kWh battery storage and 2 x 5kW hybrid inverters.
Hmm, could start off small and add to this then?

Can you link to where you could source please?
A number of members on here (Joeboy included) have purchased batteries from Shenzhen Deriy, and Colin Deng (who works there) is also a member.
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nowty
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Re: DC Battery storage into Tesla Powerwall

#15

Post by nowty »

Moxi wrote: Tue Feb 07, 2023 2:02 pm Not a problem if you use a separate charger and use the grid tie inverter to just feed the system though. You could set the charger on timer to take advantage of any tariff you might be on or even add in DC charging if you have the space for more panels.

The possibilities are endless :)

Moxi
So I use a battery inverter Sofar ME300SP as a supplementary battery charger in "dumb" forced charge mode and I control it with a WiFi socket so its on or off but other folk have used them in passive mode using fancy home brewed third party hardware.

It can also do forced discharge and have it on a timer.

So I can see some straight forward possibilities, at least on a manual or a simple semi automatic way.
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